Definition of x rays:
(n) :
Short wavelength electromagnetic radiation usually produced by bombarding a metal target in a vacuum. Used to create images of the internal structure of objects; this is possible because X-rays pass through most objects and can expose photographic film.
(n) :
A radiograph: a photograph made with X-rays.
(v) :
(transitive, informal) To take a radiograph of; to obtain an image of using X-ray radiation, especially for the purpose of medical diagnostic evaluation.
(n) :
An X-ray machine.
(adj) :
Of or relating to X-rays.
(n) :
(chess) A tactical motif where a piece exerts influence or control over a square, piece, or line indirectly through another intervening piece.